I'm working with eclipse indigo 3.7.
I also installed m2e plugin version 1.0.100.20110804-1717.
There is only one installed jre : jdk1.6.0_23 (c:\....\jdk1.6.0_23)

If I do new maven project ... create a simple project (or any other archetype), the project is created with jre system library : J2SE-1.5 containing some jars from c:\....\jdk1.6.0_23\jre\lib. And a warning message :
Build path specifies execution environment J2SE-1.5. There are no JREs installed in the workspace that are strictly compatible with this environment. JRE System Library Problem.